This invention relates to computer modeling, and in particular, to the creation of geometric models from digitized data.
Advances in computer technology have made possible realistic and accurate three-dimensional (3D) computer models of real-world objects. Such capability provides a way to prototype and test new designs quickly and cost-effectively. One method of creating these 3D models is to generate them using software which creates polygon meshes or mathematical representations of objects. Users of 3D computer modeling technology, however, are increasingly finding that some objects are easier to build as physical parts, for example using a traditional sculpting process, rather than through software-based 3D modeling techniques. To complete the overall modeling process, a computer representation of these physical models is needed. This can be accomplished, among other ways, through the use of scanning technology.
With recent advances in scanning technology, the use of digitized data is becoming an important part of the geometry creation process for designers and animators. Physical models can be scanned using a scanning system, producing a database of 3D points which can then be processed in software to produce curves and surfaces representative of the physical objects. A typical scanning process results in several scans of an object, producing several thousand to several million 3D points. These scanning devices may generate dimensional data using contact as well as non-contact techniques. For instance, the surface of an object may be traced by a tracer disk, a stylus or a touch probe scanner. Alternatively, an optical beam such as a laser beam may be irradiated on the exterior contours of the object and imaged onto a position detector. Using these various techniques, the 3D shape measuring device can generate a complete spatial description of the object as a cloud, or set, of points.
However, since computers have finite storage and processing capacity, it is undesirable to model an object with an infinite number of coordinate points. Moreover, these points may not be edited or manipulated easily by tools which expect the object to be represented mathematically by curves or surfaces.